The light weight 2 stroke engine, a 3
cylinder "Triple" model pictured here. This image is of the
front of the engine where this models exhaust exits. The
water pump is visible on the lower left behind the "right
front" motor mount. On the right of the photo is the
crankshaft PTO output where the "primary" or "drive" clutch
is normally installed. On the opposite end is the "recoil"
or "pull start" housing.
The crankshaft that goes around
and around and similarly to a bicycle pedal crank, in which
also the pedals are pumped up and down.
So instead of pedals being pumped
up and down like on a bicycle, combustion "pumps" the
pistons up and down which in turn spins the crankshaft.
This is the variable speed clutches,
the smaller diameter "primary" or "drive" mounted on the
engine crankshaft. And the larger diameter "secondary" or
"driven" clutch. The fit, deflection and width of the drive
belt is absolutely critical to proper snowmobile operation.
Photo 1 is the die cast balanced and
matched primary assembly. Photo 2 is the protruding 3 arm
spider with roller against calibrated weight, restrained at
idle by the drive spring. Photo 3 shows the drive clutch
exposing the drive sheaves on which the belt is manipulated.
Photo 4 is the driven clutch helix and driven spring. You
can see where the bushings move on the shaft, when the
clutches shift in unison and the sheaves open for higher
Where the "rubber meets the road" as
the old saying goes. This is a "121 inch" model 15 inches
wide with 1 inch treads adequate for a 90HP sled that can
run on a groomed trail with out worry of over heating
suspension and drive components.
Also visible is the extruded aluminum heat exchangers
mounted under the running boards. These heat exchangers
permit the liquid cooled snowmobile engines to run at a low
stable temperature contusive to making twice the staying
power of comparably sized air cooled models.
High quality skis and "Dually"
carbides round out a good handing package. A skid plate adds
integrity to the plastic belly pan and protects the chassis
from some of the obstacles hidden in the snow.
The plastic "sliders" or "hyfax" is red and visible thru the
open windows created in the track for lubrication and